Submarine signaling apparatus



June 13, 1950 J. T. BEECHLYN 2,511,689

SUBMARINE SIGNALING APPARATUS Original Filed Feb. 28, 1944 2 Sheets-Sheet 1 lllll Hill I IN! ENTOR.

JOHN T. BEECHLYN HGA FIG.3 By

June 13, 1950 J. T. BEECHLYN SUBMARINE SIGNALING APPARATUS 2 Sheets-Sheet 2 Original Filed Feb. 28, 1944 .1 lllllllllll llflllll llv ll lllhiul lllur llllllllll In FIG. 6

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?atenied June 13, 195i) 2,511,689 'SUBMARINE srouanmc APPARATUS John T. Beechlyn, Boston, asslgnor to Raytheon Manufacturing Company, a corporation of Delaware Original application February 28, 1944, Serial No. 524,989, now Patent No. 2,443,177, dated June 15, 1948. Divided and this application February 11, 1947, Serial No. 727,922

Claims.

sending and receiving compressional waves'and more particularly to a magnetostrictive device adapted to be used in a fluid and liquid medium for the transmission of compressional waves in sub-audible, audible or super-audible range. The invention is particularly applicable to submarine signaling both for transmission and for reception and may therefore be called a transducer which is commonly applied to devices capable of translatin compressional energy to. electrical energy or vice versa. The device may also be used as a transceiver for transmitting and receiving compressional waves. The design of magnetostrictive devices for the transmission and reception of compressional waves has brought into'common use certain types of these devices which operate successfully for the purposes to which they are applied. Among the commonly used devices are so-called magnetostrictive oscillators built up of laminations forming blocks through which coils are threaded in a number of ways, most of which are resonant at a desired frequency. Another known type of magnetostrictive oscillator or transceiver is one in which one or more tubes are surrounded by coils producing longitudinal varying flux which creates corresponding mechanical motion. A plate or sound radiator at the end of the tube provides a coupling with a propagating medium.

The present invention differs from the art briefly described above and from other devices in a number of features which provide definite advantages under many circumstances where the present device is to. be used. The arrangement accordin to the present invention may be built up into almost any desired form of radiating surface, itself occupying substantially a rectangular casing with desired elongated dimensions, or a circular casing with elongated dimensions so that the device may be placed in a desired position in the water to produce the most favorable results. However, it should also be noted that the radiating surface consists of the tubes directly moved by the magnetostrictive forces and having the water medium only on the outer side of the tube. No diaphragms are used in the present device. A chief advantage in this connection is that the apparatus is comparatively light in proportion to its size, and can easilybe used and manipulated in the water in connection with overboard devices Z2 and floating devices or devices which may be fixed with anchorage in definitely chosen spots.

The apparatus isalso adaptable for use with a parabolic or hyperbolic reflector for directive transmission and reception in a beam or in a fan-shaped plane and for this purpose the sound characteristic pattern is made up of arrangements of groups of tubes covering the space over which radiation is desired to be provided. As regard. the acoustical properties and advantages of the present construction, it is desirable to point out that resonance Of the structure is produced for a motion of the structure against which no direct radiation damping occurs. In this respect a group of independently vibrating longitudinal sections is used in which resonance may be established for the longitudinal length, whereas the actual radiation into the medium occurs through the transverse expansion and contraction of the tubes.

Further the design of the present invention is particularly adaptable for providing either a sharply tuned or broadl tuned system, since the device has two modes of resonance, the longitudinal and the transverse, which are coupled inherently in the tubes of the device. These and other features will be more fully described in connection with the specification annexed hereto describing the invention as illustrated by the drawings, in which Fig. 1 shows an elevation of the invention with parts in fragmentary section; Fig. 2 shows a section taken on the line 22 of Fig. 1; Fig. 3 shows a broken section through a modification of the invention shown in Fig. 1; Fig. 4 shows a cross-section through a further modification of the invention corresponding to a transverse cut of the section of Fig. 3; Fig. 5 shows a broken section with parts in fragmentary view of a still further modification of the invention shown in Fig. 1; Fig. 6 shows a section taken substantially on the line 6-6 of Fig. 1; Fig. 7 shows a section taken substantially on the line l--l of Fig. 5; Fig.- 8 shows a device in accordance with Fig. 4 or 5 used with a reflector; and

Fig. 9 shows a set of resonance curves relating to the operational characteristic of the apparatus.

In the invention shown in Figs. 1, 2, and 6, the invention comprises mainly a group of tubes (1, 3, c, 5, 6 and i which are made of magnetostrictive material through which is threaded one or more electrical conducting wires 2, longitudinally the length pf the tube as indicated in Fig. 1. This wire may be threaded down through one tube and up through the next tube and passing in this maer through all. of the tubes. ve a single 3 turn is shown in Fig. 1, the conductor 2 as indicated in Fig. 2 may comprise a group of wires and also the manner of threading the wires may be in accordance with any desired arrangement. For instance, the wires may be looped through any pair of tubes, as shown in Fig. 3, or may be looped through some pairs of tubes first before entering the other tubes. The main purpose of the arrangement of the conductors is to establisha magnetic flux in the magnetostrictive tube members I, 3, 4, 5, 6, I which circulates around the circumference or wall of the tube. The tubes are opened at each end, as indicated in-Fig. 1, and are set in and sealed at both ends in retaining plates 8 and 9 forming parts of enclosing chambers from which the liquid propagating medium is excluded. The retaining plates 8 and-:9 at each end form end supports which are supported by the external casing I0, which is provided with end walls II and I2 and side walls Hand l4. These walls are perforated by holes |-l5, et cetera, to permit the propagating medium or liquid, as for instance water, if the device is used for signalling in water, to enter into the chamber formed within the casing for the purpose of filling the chamber and surrounding the tubes with the propagating or radiating medium but no liquid enters into the'tubes. The tubes l, 3 et cetera may be made ofthe same or different diameters andmay bedi'vided into independent vi- I brating sections by projecting flanges l1, l8, l9

and 20. These flanges are formed by any suitable means which bend out the walls of the tubes forming a narrow U shaped section as viewed in Fig. 1. This type of joint between any two sections of the tube, as for instance, sections 2| and 22, permits the sections to vibrate longitudinally unimpeded, without any substantial recirculates through the walls of the tube in directions concentric with the axis of the tube. As is well known, magnetostrictive tubes made of nickel undergo an increase in flux in response to a contractive force. and vice versa an increase in flux produces a contractive action which' tends to contract the tube sothat when the flux increases, the circumference of the tube decreases. Whether thisis a primary or a secondary effect has not been scientifically established but, with the alternate expansion and contraction of the diameter of the tubes due to the alternating flux in the tubes, a corresponding longitudinal vibration takes place in the tube section and if this longitudinal vibration is established for the longitudinal resonance of thetube, then the mechanical forces in the tube act at resonance to enhance the lateral contraction and expansion amplitude of the tube itself. The longitudinal resonance of the tube is unimpeded from the point .of view no radiation occurs because of this motion and therefore no water load is impressed upon the tube merely by means of this longitudinal vibration. The lateral expansion and contraction of the tube acts against the propagating medium to impart vibrations to the medium and this furnishes the comparatively large water load with small linear amplitude as compared to the larger longitudinal linear amplitude of the sections of the tubes. The radiation of each tube section will be in the same phase so as to prevent the liquid within the casing I5- from leaking out into the end chambers 23 and 24 into which the conducting wires extend where electrical terminals and joints may be made and assembled. The end chambers 23 and 24 are .formed by the plates 8 and 9 over which are placed cover members 25 and 26 which are sealed to the end plates by suitable gaskets or flanges 21 and 28 which are clamped between flanges 29 and an of the covers by means of the bolts 3| et cetera for the flange 29 and 32, 32 et cetera for the flange 30. The cover member 25 may have a cable fitting 33 through which the cable 34 is sealed. This construction will prevent the liquid from entering into the inside of the tubes and also acting on the electrical conductors. It is very necessary that the insides of the tubes be kept free from external liquid in order to avoid damping of the tubes if the liquid were within the tubes.

Asindicated in Fig. 2, if radiation is desired only through one side of the casing, the other side may be lined with an acoustic reflecting layer 35 which may be cork with a plastic binder,

as for instance the material called Corprene, t or any other suitable sound reflector may be used.

The spacing of the tubes from the reflecting wall gated waves so as to build up the radiation amplitude. If the tubes are spaced substantially a quarter of a wave length from the reflecting wall;

then the reflected wave from the wall will be substantially in phase with the wave radiated from the tube in the direction normal to the reflecting wall. tube lengths 2| and 22 may be given a' longitudinal resonance-for the wave to be propagated or received while the lateral hoop resonance of the tube is made higher than that at which the device is intended to operate.

In the description of some of the other arrangements it will be pointed out how the longitudinal and lateral or hoop resonance maybe established at the same or nearly the same value and how this inter-action of the two resonances may be used to establish and broaden the resonance curve which is particularly useful for the device when it is used as a receiver of noise or broad band signals.

The arrangement shown in Fig. 3 may-be used with a single pair of tubes or with groups of tubes forming two lines, one of each line form- The arrangement shown in Fig. 3: also differs, however, from that 01' Fig. 1 in its ing a pair.

, structural effect. In this case the tubes 40 and 4| may be substantially larger than the corresponding ones of Fig. 1 or they may have a large number of longitudinal sections separated by the connecting flanges 42, 43, et cetera. The

top end of the tubes may be supported in a frame 44 in which the ends of the tubes are hermetically sealed. The frame 44 may be provided with an outwardly extending flange 45 which is clamped between two collars or rings 46 and 41, the ring or collar 41 being the end element of a cover or casing 48 enclosing the end of the device. The flanges 46 and 41 are held together by means 01 the screws '49 which thread In the arrangement just described, the

through theflanges 46 and 41 and pull the flange 45 against the face of the flange 46 between which elements a clamping ring 50 is positioned to effect a water-tight seal. A conductor enters through a packing gland 52 at the top of the casing 48 and this conductor 5| carries the conducting wires 53 and 54 which are the terminals nection with Fig. 1, namely the alternating flux expanding and contracting the tubes laterally provides a lateral radiation of the compressional waves. The longitudinal lengths of the section may here also be designed to provide a longitudinal resonance at the frequency at which the devices will operate. The tubes 40 and 4| may be surrounded with a shell 58 which may be welded to the inside of the flange 46. This shell may have perforations so as to permit the entrance of the propagating liquid or fluid medium.

In Fig. 4 a section is shown through a modification in which a number of tubes are arranged uniformly in a circular or polygon shape. Each of these tubes 50, 6|, 62, 63, 64 and 65 may be retained and supported in a manner similar to that shown in Figs. 1 and 3, and the coil 66 may be threaded in and out of the tubes in the same manner as that shown in Figs. 1 and 3. The threading of the coil in the tubes may be in series or series parallel or in any desired arrangement. The tubes of Fig. 4, like those of Figs. 1 and 3, are sealed against fluids and liquids, but are immersed in the chamber 61 which may be filled with the propagating medium and which is protected by means of the shell 58. The operation of the device according to Fig. 4 is similar to that described in connection with Figs. 1 and 3.

In the arrangement shown in Figs. 5 and 7 the construction is such as to send the flux lengthwise in the magnetostrictive tube. Here the magnetostrictive tube 10 is of the same type as described in the previous modifications with sections of the tube I, 12 joined by coupling flanges 13 which permit each tube to vibrate independently both in the longitudinal and transverse direction. These tubes may be of such a diameter that they have a so-called hoop resonance at the same resonant point as the longitudinal resonance of the sections. The tube is supported at its ends in top and bottom heads 14, and I5, respectively. Within the magnetostrictive tube 10 there is positioned an assembly comprising an innerlaminated core 16 surrounded by a coil 11 wound on an insulating form 78 which may be of Bakelite or other suitable material. The form fits closely to the core and the coil carries the alternating current for vibrating the tube or acts to pick up the currents received by the system, depending upon what use the device is put to, whether a transmitter or receiver. Surrounding the coil and fitting close to the coil form is a shell 19 which may be concentric with the inner core and the coil and which is a permanent magnet made of such material as Alnico or other highly permanent magnetizible metal. As indicated in Fig. '7, this shell 19 is split as at 80 to'prevent the circulation of eddy currents. A collar 8| is placed around the top of theform 18 to which it fits snugly and about this collar fits the sleeve 82 which has an internal recess 83 holding the end of the tube 10. The sleeve 82' is recessed on the outside to receive the tubeor shell 84, of copper or other conductive material, for purposes or confining the alternating magnetic flux within the shell of the tube. The top of the device is made watertight by means of the packing gland 85 which is clamped by means of the screws 86 to the ends of the sleeve 82. The cable 81 is led through the packing gland and connects by means of the wires 88 and 89 to the coil Tl.

In the arrangement as described, the coil carries the alternating flux at the frequency at which the vibrations in the tubes are to be produced. Normally with no current flowing in the coil 11, the return magnetic path for the perma nent magnet is divided, part flowing through the magnetostrictive tube and the other part flowing through the laminated central core. When alternating current flows through the coil, the direct current flux through the laminated core is alternately opposed and aided by the alternating current flowing through the coil. This action will unbalance the portion of the constant flux flowing through the magnetostrictive'member, and the reaction of this and of the alternating flux through the laminated core will vary the flux through the magnetostrictive member in accordance with the variation of current flow through the coil. The outside tube 84, which provides in eifect a short-circuited secondary coil, acts through the eddy currents circulating in it to confine the magnetic flux emanating from the permanent magnet to flow through the magnetostrictive tube rather than to spread out in the space beyond the wall of the tube. The variation in longitudinal flux in the magnetostrictive tube will produce a longitudinal vibration and a corresponding transverse vibration in the form of a lateral expansion and contraction of the tube. The diameter of the magnetostrictive tube may be so chosen that its hoop resonance or the resonance in the motion of the lateral expansion or contraction is of the same frequency as the longitudinal resonance between coupling flange sections of the tube.

In Fig. 9 a set of curves is shown illustrating the combination of resonance of the system due to the longitudinal and transverse resonance peaks. The curve 90 may be the curve corresponding to the longitudinal resonance of the tube sections while the curve 9| may correspond to the hoop or lateral resonance of the tube sections. These resonance peaks may coincide with the axis 92 or, if desired, they may be separated by a small frequency difierence. When the two resonance peaks are so separated, the coupling of these two resonance modes of the system produces a broadened resonance curve, as illustrated by 93, in which there are two peaks A and B, one corresponding to longitudinal resonance and the other corresponding to transverse resonance. The tuning in this case has a band width substantially between vertical lines C and D whereas the individual resonance elements have a much narrower band width. For reception purposes, a resonance system is obtainable which has a considerable breadth for tuning over the receiving range. The device of this nature may be designed for reception over a broad supersonic band or over a narrower sonic band, depending upon the dimensions and couplings in the system. In a closely coupled structure where most where the coupling is not so close. In systems- .such as the present case where the masses of the moving parts are quite small, the coupling inaybe very close and therefore the system may be broadly tuned, that is, tuned over a wide band.

,In the arrangement shown in Fig. 8, a device such as disclosed in Fig. 4, or, in fact, some of the other figures, may be used. Here thetube- 98 may be set at the locus 01' a parabola or o! the corresponding point of a rectangular hyperbola or any other reflecting body such as the reflector 95. The reflector may, if desired, be turned about the tube 88 as the axis both for directively sending and for reception.

for the tube I is in the section just beyond thecoupling flange section 98 leaving the tube 12 substantially free for longitudinal and transverse,

vibrations. The external tube 94, as indicated in Fig. 5, fits around a shouldered recess 91 formed in the end'cap 98. The inner side of the end cap 98 has also a recessed shoulder 99 in which the end of the tube 19 is supported. The inner portion of the end structure is similar to that at the top of the structure, with the laminated core 19 extending down to the base of the cap 98 and the bottom of the form 18 on which the coil I1 is wound extending also down to the base of the cap 98.

Having now described my invention, I claim:

1. Means for sending or receiving compressional waves comprising amagnetostrictive tube having flexible coupling sections dividing said tube into independently vibratable portions, a permanent magnet formed as a shell positioned concentrically within said magnetostrictive tube, a core positioned within said shell having material permeable to magnetic flux, and means surrounding said core for producing alternating magnetic flux in said core, the ends of said core and said magnet being substantially adjacent to said tube whereby the flux in either one element may circulate through the other element.

2. Means for sending or receiving compressional waves comprising a magnetostrictive tube having flexible coupling sections dividing said tube into independently vibratable portions, a permanent'magnet formed as a shell positioned concentrically within said magnetostrictlve tube, a core positioned within'said shell having material permeable to magnetic flux, and means surrounding said core for producing alternating magnetic flux in said core, the ends-oi said core and said magnet being substantially adjacent to said tube whereby the flux in either one element may circulate through the-other element, said magnet shell being split longitudinally the length thereof.

3. Means for sending or receiving compressional waves comprising a magnetostrictive tube having flexible coupling sections dividing said tube into indcpendently vibratable portions. a

permanent magnet formcd as a shell pomtioned concentrically within said magnetostrictive tube, a core positioned within said shell having material permeable to magnetic flux, and coil means surrounding said core for producing alternating magnetic flux in said core, the ends oi said core and said magnet being substantially adjacent to said tube whereby the flux in either one element may circulate through the other element, means for supporting the ends of said magnetostrictive tube, said magnet and said core, and electrical conducting means, connected to said coil i'or energizing the same.

4. Means for sending or receivingcompressionalwaves comprising a magnetostrictive tube having flexible coupling sections dividing said tube into independently vibratable portions, a permanent magnet formed as a shell positioned concentrically within said magnetostrictlve tube. a core positioned within said shell having material permeable to magnetic flux and means surrounding said core for producing an alternating magnetic flux in said core, the ends of said core and said magnet being substantially adjacent to said tube whereby the flux in either one element may circulate through the other element and an electrically conducting shield member spaced from and surrounding said magnetostrictive tube.

5. Means for sending or receiving compressional waves comprising a magnetostrictive tube, a permanent magnet formed as a shell positioned concentrically within said magnetostrictive tube, a core positioned within said shell having material permeable to magnetic flux and means surrounding the core for producing an alternating magnetic flux therein, the ends of said core and said permanent magnet being substantially adjacent to said magnetostrictive tube whereby flux in either the permanent magnet or the core may circulate through each other and the magnetostrictive tube for alternating the flux intensity in said magnetostrictive tube to produce longitudinal and transverse vibrations.

JOHN T. BEECHLYN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,985,251 Hayes Dec. 25, 1934 2,153,571 Kallmeyer Apr. 11, 1939 2,269,760 Eldredge Jan. 13, 1942 2,407,243 Batchelder Sept. 10, 1946 2,452,085 Turner Oct. 26, 1948 FOREIGN PATENTS Number Country Date 818,828 France Oct. 4, 1937 394,994 Great Britain July 5, 1933 

